The semiconductor integrated circuit (IC) industry has experienced rapid growth. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. However, these advances have increased the complexity of processing and manufacturing ICs and, for these advances to be realized, similar developments in IC processing and manufacturing are needed. In the course of IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometry size (i.e., the smallest component (or line) that can be created using a fabrication process) has decreased. This scaling down process generally provides benefits by increasing production efficiency and lowering associated costs.
As the scaling down process continues to advance, defect reduction becomes more important. For example, during a photolithography process, insufficient removal of a developer solution may lead to wafer surface defects such as water stains or photoresist scum. These defects adversely impact semiconductor device performance. The ever-smaller feature sizes (as devices are scaled down) may further increase the difficulty of removing the developer solution or other defects from the wafer surface.
Therefore, while existing semiconductor fabrication processes have been generally adequate for their intended purposes, they are not entirely satisfactory in every aspect.